Photographic treating apparatus



Jan. 27', 1970 N. sou:

PHOTOGRAPHIC TREATING APPARATUS 3 Sheets-Sheet 1 Filed May 8, 196'? INVENTOR o d ib/wuwv wrwl W (11ml E g I PHOTOGRAPHIC TREATING APPARATUS 3 Sheets-Sheet 2 Filed May 8, 1967 FIG.2

a INVENTOR. mm $9M BY m d m fighdJwm ATTORNEYS United States Patent 3,491,675 PHOTOGRAPHIC TREATING APPARATUS Nicholas Gold, Arlington, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Filed May 8, 1967, Ser. No. 636,944

Int. Cl. G03d 3/00 US. Cl. 95-89 20 Claims ABSTRACT OF THE DISCLOSURE A liquid applicator including a reservoir for holding a quantity of liquid and a container for replenishing the supply of liquid in the reservoir. The container has a conduit for feeding liquid to the reservoir, an air vent for providing a barometric feed of liquid to the reservoir, and a layer of oil or a protective bellows-type member on the top surface of the liquid in the container for protecting the processing liquid from the air admitted by the vent. The reservoir has a capillary slot for applying liquid to the web being treated, and a diaphragm attached to the reservoir for controlling the flow of liquid from the container to the reservoir in predetermined levels. When the liquid in the reservoir has reached the predetermined level, the diaphragm cooperates with the air vent of the container to prevent any further barometric feed of liquid to the reservoir.

This invention relates to a novel apparatus for supplying liquid to a reservoir and controlling the level of liquid in the reservoir while simultaneously essentially isolating the liquid from the atmosphere. Photographic apparatus is disclosed in which the reservoir is a component of a liquid applicator including capillary means for withdrawing the liquid from the reservoir and applying it to an exposed photosensitive sheet. The liquid is supplied in a closed container mounted above the reservoir and connected thereto by a conduit. The container is provided with a vent for admitting air to the container to allow liquid to flow therefrom through the conduit to the reservoir, and control means are provided for closing the vent when the level of liquid in the reservoir is above a predetermined level and opening said vent when the level of liquid is below a predetermined level.

The invention further relates to novel apparatus for controlling the level of liquid in an applicator and, more particularly, to apparatus used in controlling the amount of processing fluid available in an applicator of the type used in photographic apparatus, e.g., document copiers.

A number of photographic processes involve the application of a nonviscous liquid reagent to a photographic sheet. In a typical process, the reagent may include a light-sensitive material, a sensitizer, a reagent for processing an exposed light-sensitive layer to produce a visible image or a composition for protectively coating and/or treating a visible image. The present invention is particularly concerned with the application of liquid reagents employed to produce a visible image in a layer of an exposed light-sensitive image-recording sheet material, in apparatus such as a camera, document duplicator or the like, in which the light-sensitive material is exposed. Liquid processing reagents employed for the latter purposes are generally highly alkaline and subject to deterioration due to evaporation and contact with the atmosphere, thus requiring that the liquid be confined in such a way as to protect and preserve its quality and stability.

Delivery of the liquid from a reservoir to a sheet and accurate metering as well as uniform distribution of the liquid on a surface of the sheet may be achieved by a capillary through which the liquid flows by capillary action. In such a case the quantity of liquid applied is directly related to the height of liquid in the reservoir as well as the width of the capillary channel and the linear rate of movement of the sheet past the capillary channel.

Accordingly, an object of the present invention is to provide novel and improved means for automatically controlling the level of liquid in an applicator.

Another object of the invention is to provide novel means as described, in which the liquid is protected from the deleterious effects of the atmosphere.

Another object of the invention is to provide novel means as described, in which the liquid is moved from a reservoir to a sheet by capillary action.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIG. 1 is a sectional, elevational view of photographic apparatus embodying the invention;

FIG. 2 is an enlarged sectional view of a liquid applicator and level control constructed in accordance with the invention;

FIG. 3 is an enlarged sectional view of another embodiment of the liquid applicator and level control;

FIG. 4 is a schematic showing of another embodiment of the liquid applicator and level control; and

FIG. 5 is a further schematic showing of another embodiment of the liquid applicator and level control.

Reference is now made to FIGURE 1 of the drawings wherein there is illustrated document-copying apparatus embodying the invention. The document copier comprises means for exposing successive areas of a combined image-recording and image-receiving sheet, severing successive sections of the sheet, each containing an exposed area, from the remainder of the sheet and means for processing the successive sections of the sheet including means for applying a nonviscous (e.g., viscosity of water) liquid reagent to one side of each of the sections.

The apparatus comprises exposure means including a window 10 in the upper wall of the housing of the apparatus for supporting an original, e.g., document, in position for exposure to light from lamps 12 mounted within an enclosed chamber separated from the remainder of the interior of the housing by a lower wall 14 and a side wall 16. Light reflected from an original positioned on window 10 is transmitted by a conventional objective lens, part of a lens and shutter assembly 18 toward a focal plane in the apparatus at which the lens forms an image of the original. The optical system includes, in addition to the lens of assembly 18, a mirror 20 positioned beneath the lens for reflecting light toward one side of the housing and means for supporting a light-sensitive image-recording sheet at the focal plane of the lens.

A supply of light-sensitive, image-recording sheet material, designated 22, is provided coiled on a spool 24 in the lower portion of the apparatus behind mirror 20. The means for positioning successive sections of the sheet in position for exposure include a support plate 26 and a juxtaposed transparent plate 28 located in a vertical plane with the surface of the transparent plate located substantially at the focal plane of the lens. Sheet 22 is withdrawn from spool 24 and moved upwardly between plates 26 and 28 by a pair of juxtaposed feed rolls 30 located beneath and adjacent to the lower edges of the plates.

A rotary knife 32 and anvil 34 are mounted above and adjacent the upper edges of plates 26 and 28 for sever-v ing successive exposed sections of the image-recording sheet as each section is advanced upwardly from between the plates between the knife and anvil. In the operation of the apparatus, a section of the image-recording sheet positioned between plates 26 and 28 is advanced, following exposure, upwardly past the knife into engagement with liquid applicator means and then through a sheet conveyor system designed to deliver the sheets from the applicator to an exit opening in the housing of the apparatus and to provide a delivery period of sufficient duration to permit completion of the processing of the imagerecording sheet within a dark environment. The sheet delivery system includes two sets of endless conveyor belts 36 and 38. The belts 36 are mounted on support rolls 40 and 42, and belts 38 extend from support rolls 44, juxtaposed with support roll 42, upwardly in juxtaposition with belts 36 and around an enlarged drum or discs 46 and thence back to support roll 44 by way of support rolls 48 spaced around the periphery of drum or discs 46. The conveyor belts 38 which contact the side of the sheets to which the liquid is applied are preferably quite narrow in order to limit the area of contact between the belts and the sheet, and in the preferred form, may comprise conventional O-rings.

The housing of the apparatus includes an opening 50 through which the processed sheets are delivered and a pair of guides 52 extending from the opening upwardly toward the points of tangency between belts 38 and discs 46 for guiding the sheets from between the belts and discs downwardly through opening 50.

The liquid applicator and level control of the invention is designated 54 in FIGURE 1 and is shown in detail in FIG. 2 as comprising an elongated container 56 including a chamber 84 for holding a quantity of the processing liquid 58. Container 56 and the chamber 84 containing a processing liquid are approximately equal in length to the width of the area of the photosensitive sheet material to be treated. Applicator 54 includes a section providing a generally planar support surface 60 at least equal in length to the width of the sheet material to be treated for guiding and supporting the sheet material during application of the processing liquid. Support surface 60 terminates at one side of a capillary channel or slot 62 at least equal in length to the width of the area of the sheet material to be treated and having a width of capillary dimensions such that an aqueous alkaline liquid having a viscosity substantially that of water will flow through channel 62 by capillary action. Applicator 54 includes a section on the opposite side of channel 62 from surface 60 providing a surface 64 set back from surface 60 by approximately the width of capillary channel 62. The applicator including the portions thereof providing the container for the processing liquid, surfaces 60 and 64 and capillary channel 62, may be formed of any material that is compatible with the processing liquid and preferably a material that is wet by the processing liquid in order to encourage flow thereof by capillary action. Suitable materials include organic polymers such as the acrylics, glass, ceramics and metals.

Liquid 58 is conducted from the chamber or reservoir 84 in which it is contained, to capillary channel 62 by a multiplicity of capillaries. In the embodiment shown, this multiplicity of capillaries is provided by a fibrous wick 66 formed, for example, of a nonwoven fabric composed of fibers of a material such as polypropylene, which is compatible with the processing liquid. Applicator 54 includes a section providing a channel 68 at least approximately equal in length to capillary channel 62 and communicating between capillary channel 62 and the lower portion of the reservoir of liquid. Wick 66 substantially fills channel 68 which, in the form shown in FIG. 2, extends from the bottom of the reservoir 84 upwardly and at an angle to a position above the level of capillary channel 62. By virtue of this construction, liquid 58 is raised within channel 68 to a level above channel 62 and provides a supply head in the capillary channel.

It has been discovered that a single capillary channel or slot provides the best means for accurately metering and uniformly distributing the processing liquid in contact with the sheet material. A multiplicity of capillaries for conducting the liquid from a reservoir 84 to the metering and distributing capillary provides assurance of adequate supply of the liquid to the capillary channel despite the clogging or plugging of a number of the supply capillaries. The invention comprehends a construction incorporating a sufflcient number of supply capillaries for conducting at least twice the amount of liquid that can be carried by the metering and distributing capillary channel.

The apparatus for automatically supplying liquid to reservoir 84 and controlling the level of liqufd in the reservoir 84 is most clearly shown in FIG. 2, as comprising a closed storage tank or container 72 having a supply of processing liquid therein. Container 72, which is mounted at a higher level than reservoir 84 so as to provide a gravity flow, is fluidly connected with reservoir 84 by conduit 74. Provision is made for maintaining the liquid within container 72 substantially at ambient pressure while at the same time protecting the liquid from the air. This is accomplished by providing container 72 with a vent 76 having an end which is open to the ambient pressure at a point adjacent the top of the reservoir 84 and a flexible bellows 78 secured in the container to the walls thereof so as to protect the liquid from air admitted through vent 76. Other suitable means, e.g., as shown in FIG. 1, a layer of oil on top of the processing liquid, could be substituted for the bellows-type member 78. In the latter case a vent 98, similar to vent 76 would extend directly through the processing liquid and oil and emerge in the area above the oil. Referring again to FIG. 2, vent 76 has an opening 80 adjacent a diaphragm 82 attached to the walls of the reservoir 84. Diaphragm 82 may be made of any material that is compatible with the processing liquid. When the processing liquid in reservoir 84 is above a predetermined level the liquid will cause diaphragm 82 to flex into a position closing the opening 80 of vent 76. As the developing liquid is applied to sheet material 22 container 72 replenishes the liquid taken from the reservoir 84. After a period of time the liquid in storage tank 72 is prevented from flowing into the reservoir 84 due to the lower pressure created in the area above the liquid. This lower pressure is due to the expanding volume of the gas in that part of storage tank 72 above the level of the liquid. Continued use of the developing liquid will lower the level of liquid in the reservoir 84 to a point below a predetermined level where diaphragm 82 is allowed to flex to a position uncovering opening 80 of vent 76. With vent 76 now open, the pressure on the fluid in storage tank 72 is increased to that of the ambient pressure thereby allowing liquid to flow from container 72 to the reservoir 84. It should be noted that the cross-sectional area of opening 80 is substantially smaller than the area of the diaphragm 82. At times the pressure in vent 76 will be lower than the pressure acting on diaphragm 82 thereby tending to keep diaphragm 82 in contact with opening 80 by its vacuum action. However, due to the relatively small size of opening 80 the reduced pressure in vent 76 acts on a correspondingly small area of diaphragm 82. Accordingly, due to this large differential in areas the suction or lower pressure in vent 76 does not adversely affect the responsiveness of diaphragm 82.

An alternative embodiment of the applicator and liquid level control of the invention is shown in FIG. 3. Applicator 86 is essentially the same as applicator 54 except in this embodiment the means controlling the liquid level is remote from the reservoir. Closed container 172 is fluidly connected to a secondary reservoir 88 by conduit means 174. Container 172 is vented to the ambient pressure by vent 176 and the liquid in container 172 is protected from the adverse effects of the atmosphere by means such as a layer of oil 178 as in FIG. 1. Vent 176 has an opening 180 therein which is closed by diaphragm 182 when the liquid in reservoir 88 is above a predetermined level and is uncovered when the liquid in reservoir 88 is below a predetermined level thereby allowing liquid to flow from container 172 to secondary reservoir 88. Secondary reservoir 88 is fluidly connected with reservoir 184 by conduit 90. With the above arrangement of elements greater flexibility in the positioning of the elements is available. For example, reservoir 88 could be located outside of the photographic apparatus so as to be easily accessible for inspection of diaphragm 182 and opening 180.

Another embodiment of the applicator and liquid level control of the invention is shown in FIG. 4. Applicator 200 is similar to the applicator shown in the previous embodiments. Container 202 containing a developing liquid is pressurized by a gas 204 such as nitrogen. Obviously, any gas which is compatible with the developing liquid may be used as the pressurizing means. Container 202 is fluidly connected with reservoir 206 by means of conduit 208 having valve 210 therein. Valve 210 is actuated by a lever member 212 having a vertical extension 214 adjacent diaphragm 216 which is attached to the walls of reservoir 206. When the level of liquid in reservoir 206 is above a predetermined value, diaphragm 216 is in contact with the end 214 to maintain the valve 210 in a closed position. When the level of liquid in reservoir 206 is below a predetermined value, diaphragm 216 flexes downwardly allowing member 214 to follow it, thereby opening valve 210 to allow fluid to flow from container 202 into reservoir 206.

A further embodiment of the applicator and liquid level control of the invention is shown in FIG. 5. In this embodiment, container 302, containing a developing liquid charged by means such as nitrogen 304, is fluidly connected with reservoir 306 by means of a conduit 308 having a valve 310 therein. An electrical circuit is shown for actuating the valve 310. As shown, the circuit comprises energy means such as a battery 312, a relay 314 and switching means 316. Switching means 316 consists of a switch 318 having a portion 320 in contact with diaphragm 322. Valve means 310 is normally in the closed position. When the level of liquid in reservoir 306 is above a predetermined value, switch 318 is open as shown. When the level of liquid in reservoir 306 falls below a predetermined value, switch 318 is closed thereby ener gizing relay 314 to move valve 310 to an open position thereby allowing fluid to flow from container 302 to reservoir 306 by means of conduit 308.

It will be understood that the conduits and vents may be made from rigid or flexible materials as long as the material is compatible with the processing liquid. If the vents are made from a flexible material, suitable means will be provided for holding the openings 80, 180 in a position adjacent their respective diaphragms. Also reservoir 88 and/or storage tank 72, 172, 202, 302 may be mounted exteriorly of the photographic apparatus.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A photographic processing apparatus for applying, to an exposed photosensitive element, a predetermined, uniformly distributed quantity of processing liquid subjectto deterioration when exposed to the atmosphere, said apparatus comprising, in combination:

applicator means including a reservoir;

6 capillary means for conducting liquid from said reservoir to said photosensitive element, the rate of application of said liquid to said element being a function of the level of liquid in said reservoir;

a closed container for said liquid;

a conduit for conducting said liquid from said container to said reservoir; means for causing the liquid to flow from said container to said reservoir; and

control means for controlling the flow of liquid through said conduit including means attached to said reservoir for protecting the liquid in said reservoir from the atmosphere, the last-mentioned means being responsive to the level of liquid in said reservoir for arresting the flow of liquid to said reservoir when said liquid in said reservoir reaches a predetermined level and initiating flow of said liquid to said reservoir when said liquid falls below a predetermined level in said reservoir.

2. The apparatus of claim 1, wherein the last-mentioned means comprise a diaphragm supported on the surface of said liquid within said reservoir.

3. Apparatus as defined in claim 2, including means for essentially isolating the liquid in said container from the atmosphere.

4. Apparatus as defined in claim 3, wherein said control means comprise a vent operatively coupled with said diaphragm and the cross-sectional area of the opening in said vent is a fraction of the area of said diaphragm.

5. Apparatus as defined in claim 3, wherein said means for isolating the liquid from the atmosphere comprise a bellows-type member.

6. Photographic processing apparatus for applying, to an exposed photosensitive element, a predetermined, uniformly distributed quantity of processing liquid subject to deterioration when exposed to the atmosphere, said apparatus comprising, in combination:

applicator means including a first reservoir;

capillary means for conducting liquid from said first reservoir to said photosensitive element;

a second reservoir connected to said first reservoir;

a closed container for said liquid;

a conduit for conducting said liquid from said container to said second reservoir;

means for causing the liquid to flow from said container to said second reservoir; and

control means for controlling the flow of liquid through said conduit including means attached to said second reservoir for protecting the liquid in said second reservoir from the atmosphere, the last-mentioned means being responsive to the level of liquid in said second reservoir for arresting the flow of liquid to said second reservoir when said liquid in said second reservoir reaches a predetermined level and initiating flow of said liquid to said second reservoir when said liquid falls below a predetermined level in said second reservoir.

7. Apparatus for supplying liquid to a reservoir from which liquid is withdrawn and controlling the level of liquid in said reservoir comprising, in combination:

a closed container for said liquid;

a conduit for conducting said liquid from said container to said reservoir;

means for causing the liquid to flow from said container to said reservoir; and

control means for controlling the flow of liquid through said conduit including means attached to said reservoir for protecting the liquid in said reservoir from the atmosphere, the last-mentioned means being responsive to the level of liquid in said reservoir for arresting the flow of liquid to said reservoir when said liquid in said reservoir reaches a predetermined level and initiating flow of said liquid to said reservoir when said liquid falls below a predetermined level in said reservoir.

8. The apparatus of claim 7, wherein the last-mentioned means comprise a diaphragm supported on the surface of said liquid within said reservoir.

9. Apparatus as defined in claim 8, including means for essentially isolating the liquid in said container from the atmosphere and means defining a capillary for withdrawing liquid by capillary action from said reservoir.

10. Apparatus as defined in claim 9, wherein said control means comprise a vent operatively coupled with said diaphragm and the cross-sectional area of the opening in said vent is a fraction of the area of said diaphragm.-

11. Apparatus as defined in claim 9, wherein said means for isolating the liquid from the atmosphere comprise a bellows-type member.

12. Apparatus as defined in claim 7, including a second reservoir connected to said first-mentioned reservoir.

13. Apparatus as defined in claim 7, wherein said container is mounted above said reservoir and said control means include vent means for allowing air to enter said container to allow forgravity flow of liquid from said container to said reservoir.

14. Apparatus as defined in claim 13, wherein said lastmentioned means is operatively coupled with one end of said vent means for opening or closing said one end in response to changes in the level of liquid in said reservoir thereby starting or stopping the flow of liquid from said container to said reservoir.

15. Apparatus as defined in claim 14 wherein said vent means extends upwardly through the liquid in said container and means comprising a layer of oil on top of said liquid in said container for isolating said liquid from the atmosphere.

16. Apparatus as defined in claim 7 wherein said means for causing liquid to flow comprises a pressurized gas.

17. Photographic processing apparatus as defined in claim 7, wherein said last-mentioned means is movable in response to changes in the level of liquid in said reser- VOlI.

18. Photographic processing apparatus as defined in claim 17, wherein said control means include valve means, and motion-transmitting means having one end coupled to said valve means and another end coupled to said lastmentioned means for opening and closing said valve means in response to movement of said last-mentioned means.

19. Photographic processing apparatus as defined in claim 17 wherein said control means include valve means, and electrical means including switch means operatively connected with said last-mentioned means for controlling said valve means, whereby movement of said last-mentioned means in response to changes in the level of liquid in said reservoir will open or close said switch means to allow said valve means to control the How of liquid from said container to said reservoir.

20. Apparatus for supplying liquid to a reservoir and controlling the level of liquid in said reservoir comprising, in combination:

a closed container for said liquid mounted above said reservoir; a conduit for conducting said liquid from said container to said reservoir; vent means for admitting air to said container to allow liquid to flow therefrom through said conduit to said reservoir; and control means including means attached to said reservoir and movable in response to the level of liquid in said reservoir for closing said vent means when said liquid is above a predetermined level in said reservoir and opening said vent means when said liquid is below a predetermined level in said reservoir.

References Cited UNITED STATES PATENTS 2,361,818 10/ 1944 Brightwell 11840l 2,637,336 5/1953 Emery 137454 2,854,993 10/1958 Duncan et a1 l37406 3,062,123 11/ 1962 Limberger 89 3,179,033 4/1965 Limberger 9589 NORTON ANSHER, Primary Examiner FRED L. BRAUN, Assistant Examiner US. Cl. X.R. 

